We humans are a strange bunch. We have self-awareness and yet often act on impulses that remain hidden. We were forged in adversity but live in a world of plenty. Who are we? What is to become of us? To these age-old questions, science has in recent years brought powerful tools and reams of data. We know, for instance, that three million years ago, a group of primates known as the australopithecines was walking capably on two legs–the better to navigate the African savanna–and yet still had long arms suited to life in the trees. We discuss these discoveries and their interpretations in this eBook, Becoming Human: Our Past, Present and Future, which opens up with “Lucy’s Baby.” In it, author Kate Wong discusses what the oldest juvenile skeleton tells us about how early humans walked the Earth. Another article, “The Naked Truth,” examines why humans lost their hair and how hairlessness was a key factor in developing other human traits. Section Two covers “The Secrets of our Success,” and we see that human evolution and culture are often related. In “The Evolution of Grandparents,” Rachel Caspari shows us that as humans started to live longer, grandparents played a role in family life, which in turn made possible more complex social behaviors. In Section Three, “Migration and Colonization,” we look at how scientists are studying the minuscule bits of DNA that differ from one individual to another for clues to our origins and settlements. “The First Americans” illustrates the findings that have pushed back the date at which hunter-gatherers colonized the Americas. And in Section Four, “Vanished Humans,” the discovery of “hobbits”–a human species of small stature–has turned the science of human origins on its ear.

Where is evolution taking us? We present two points of view in Section Five, “Our Continuing Evolution.” Jonathan K. Pritchard, professor of human genetics at the University of Chicago, argues that selection pressure typically acts over tens of thousands of years, which means we probably won’t evolve much anytime soon. But stasis is only one possible future, says University of Washington astrobiologist Peter Ward. In adapting to new environments–say, a colony on Mars–our human species may eventually diverge into two or more. Or we could go the cyborg route and merge with machines. Whichever option you prefer, there is plenty to ponder.

* Editor’s note: Special Edition was published as Evolution: What Makes Us Human? The eBook adaptation contains all of the articles, but some artwork has been removed to optimize viewing on tablet devices.

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